The invention relates to an intake system for a mixture-compressing internal-combustion engine of the type having an electrically heatable heating element of flat form which is arranged in the intake channel downstream of a fuel-injection nozzle and transversely relative to the direction of flow and which is intended for heating the fuel/air mixture.
As is known, arranging a heating element downstream of a fuel-injection nozzle spraying into the intake channel affords an improvement of the mixture formation with the intake air flowing past and a reduction of the HC and CO emission. An intake system of this type is described in Japanese Abstracts 55-15 11 51 (Application No. 54-58, 541). In this system the fuel spread out by the fuel-injection nozzle is guided through the heating element effective at low cooling-water temperature and evaporates. The evaporated fuel is admixed with the combustion air flowing past in the intake channel and is thus fed as a heated fuel/air mixture to the corresponding combustion space in the cylinder.
An object on which the invention is based, starting from the above-mentioned intake system, is to obtain an improvement of power in the full-load mode by means of further measures.
This object is achieved according to the invention by providing an arrangement wherein the heating element is made rotatable in such a way that, above a specific engine cooling-water temperature, it can be transferred from its transverse working position into a position of rest lying in the direction of flow.
As a result of the rotatable mounting of the heating element which needs to perform its function only at specific low cooling-water temperatures, the position in the direction of flow causes no pressure losses in the intake channel and therefore also no power losses under full load.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.